Field
The present disclosure relates generally to augmented reality (AR) devices, e.g.,
AR eyeglasses, having optical see-through head mounted displays (HMD) and eye tracking capability, and more particularly, to automatic calibration of the eye tracking capabilities of such AR devices. AR is a technology in which a user's view of the real world is enhanced with additional information generated from a computer model. The enhancements may include labels, 3D rendered models, or shading and illumination changes. AR allows a user to work with and examine the physical real world, while receiving additional information about the objects in it.
Background
AR devices typically include an optical see-through HMD and one or more user input mechanisms that allow users to simultaneously see and interact with their surroundings while interacting with applications, such as e-mail and media players. User input mechanisms may include one or more of gesture recognition technology, eye tracking technology, and other similar mechanisms.
AR devices with eye tracking capability may provide for visual activation of applications and selection of files and documents, wherein activation or selection occurs when a user is looking at a displayed object corresponding to the application, file or document. In such AR devices, the displayed object, e.g., application icon, is displayed at a coordinate location of the HMD, while the location on the HMD at which a user is looking or gazing is determined using eye tracking technology. The determined eye gaze location is identified by coordinates of the HMD and may be displayed on the HMD as a point. When the eye gaze coordinates of the user are within range of the displayed object, i.e., either at or sufficiently near the coordinates of the displayed object, activation or selection of the displayed object occurs.
Effective implementation of visual activation of applications and selection of files and documents through eye tracking necessarily depends on the accuracy of the eye tracking technology. Eye tracking accuracy varies depending on environmental factors, such as light conditions, and user factors, such as eye shape and nose height. In cases where eye tracking is inaccurate, the eye gaze location or point determined by the eye tracking technology may not correspond to the location where the user is looking. Accordingly, although a user may be looking at an application icon on the HMD in an attempt to launch the application, the AR device does not recognize the attempt because the eye gaze coordinate output by the eye tracking technology is not within range of the icon.
An AR device may present a point on the HMD corresponding to the eye gaze coordinate. In such instances, the user may become aware of an inaccuracy of the eye tracking technology upon noting that the eye point does not appear where the user is looking, and as a result, initiate calibration of the eye tracking technology. AR devices, however, may not display every eye gaze coordinate in order to reduce power consumption and to minimize display real estate occupation and user distraction. As a result, a user may not be aware that the eye gaze point output by the eye tracking technology does not accurately reflect where the user is looking.